Activity: practice with lists

Instructions:

• Work with a neighbor to answer the following questions
• To get started, download the class activity template file
• When you are finished, render the file as an HTML and submit the HTML to Canvas (let me know if you encounter any problems)

Practice with lists

1. Each of the following lists contains the vector c(2, 7, 9). Determine the correct list indexing syntax to extract that vector from the list (your code should return just the vector, not a list containing the vector).

x1 <- list(c(2, 7, 9))
x2 <- list(list(c(2, 7, 9)))
x3 <- list(c(2, 7, 9), list("a", "b"))
x4 <- list(c("a", "b"), list(list(c(2, 7, 9))))

2. Create a list x5 such that the vector c(2, 7, 9) can be extracted with x5[[3]][[2]][[1]].

3. Create a list x in R such that:

• x[[1]] returns the function mean
• x[[2]] returns the function sd
• x[[3]][[1]] returns the vector c(0, 1, 2)
• x[[3]][[2]] returns a function which calculates the cube root